The Australian-trained doctor under fire for his involvement in China's controversial organ transplant program has defended the practice and responded to calls for him to be stripped of honorary titles from the University of Sydney.

China's transplant program has long been condemned and sparked protests around the world because most of the life-saving kidneys, lungs and livers used come from executed prisoners.

China has announced it is preparing to phase out organ donation from condemned prisoners.

In a rare press briefing, Dr Huang, who served as China's vice minister of health for 12 years, spoke to a small group of journalists to respond to his critics, saying Chinese prisoners must agree to have their organs harvested before they die.

"Our government already has regulations related to recovering organs from death row inmates," he said. "Consent is not presumed consent - written consent from the prisoner himself or herself as well as his or her family [is needed]."

But some say approval from prisoners condemned to death is not meaningful consent.

Medical groups, the United Nations and the World Health Organisation have criticised China for structuring its transplant program around organs taken from prisoners.

As China executes as many prisoners every year as the rest of the world combined, there has been a steady supply.

Last year there were 5,846 kidney transplants in China and more than half of the organs came from prisoners. Of all liver transplants, 80 per cent came from executed prisoners.

"We call it human value," Dr Huang said. "Everybody has a weak point and a strong point. So in the human values you can say 'he's a bad man, he's not on the good side'.

"So then before he died he found his conscience and found he needed to do something to repay society. So why do you object?"

While Dr Huang, a transplant doctor who studied at the University of Sydney, says his own practice has not taken any organs from the prisons for two years, he continues to defend the policy.

"I feel that at first I respect the donor. I think that probably he committed some very severe crime," he said.

"It's not my part, it's the judicial part to deserve the death penalty. However I respect his last will. I respect the life he donated for another three people."

Doctor recalls removing dying prisoner's organs

Enver Tohti is an ethnic Uighur from far western China who fled to London after a traumatic experience while working as a surgeon in the 1990s.

He says he was forced to remove organs from an executed prisoner.

"It was really a terrible memory," he said.

"Our surgeon told us, 'wait outside that execution ground and come in as soon as you heard the gunshot', so we did.

"There was, I guess it was a prisoner who got shot. [He had] blood and mud on his face, so our chief surgeon said, 'OK, hurry up, your task is to remove his liver and two kidneys'."

Mr Tohti says the prisoner had not yet died when they removed the organs.

I have noticed that the gun wound was on his right chest, so I guess that was deliberately to make this prisoner not die immediately to allow some time for us to remove that organ when he is still alive.

Enver Tohti

"I have noticed that the gun wound was on his right chest, so I guess that was deliberately to make this prisoner not die immediately to allow some time for us to remove that organ when he is still alive," he said.

For critics of Dr Huang, it is practices like this which mean the man previously at the helm of such a system is not worthy of his association with the University of Sydney.

However, Dr Huang says many doctors at the university are prepared to back him, despite the petition campaign led by Professor Maria Fiatarone Singh.

"I can show you a statement from Sydney University Medical School. I've got strong support from there," he said.

"I couldn't make a response to strangers... it's unnecessary for me to pay attention to them because I have my values too, I don't want to waste my time to talk about that."

Professor Bruce Robinson, dean of the university's medical school and the man who authorised Dr Huang's appointment to honorary professor, has told the ABC the university supports his efforts to reform the Chinese organ transplant program.

China calls for 'understanding'

Within the international medical fraternity there are surgeons who see Dr Huang as a liver transplant champion, who has helped usher in China's new public donation system.

The donation system is crucial because - even with prison contributions - for every one patient at a hospital receiving an organ, 30 more are waiting.

But now China says its near total reliance on prisoner donations will soon come to an end.

"I have no objections to using the executed prisoners' organ donation if he or she has freely demonstrated that this is his last will," Dr Huang said.

"However it is the Chinese Government's determination to eliminate the reliance on the usage of the criminals' organs for the main source for organ donation.

"From the progress we have made, I estimate within two years we will eliminate the heavy reliance on the prisoners' organs."

However, Professor Fiatarone Singh says she remains unconvinced.

I have no objections to using the executed prisoners organ donation if he or she has freely demonstrated that this is his last will.

Huang Jiefu

"I do believe that they are trying to move away from the system of using executed prisoners," she said.

"But the real point is, if something is unethical, then you don't suggest you are going to move away from it in a few years, you stop doing it now.

"By his own words, 95 to 99 per cent of the transplants were from executed prisoners, including the transplants that he did himself.

"So I don't see how you can give him an honorary professorship in the light of that knowledge."

But Dr Huang says the world needs to be understanding and give China a chance.

"Gradually we see China is changing, progress is being made," he said.

"It's a difficult journey. It's agony and sweat to realise the human value."